The present invention relates to a cleaning device for cleaning the magnetic head(s) of video tape recorders. After the operation of a video tape recorder for some time, the dust in the air and the magnetic dust from the video tape sticks to the surface of the magnetic head, which must then be cleaned.
Many kinds of devices have been developed for cleaning the heads of video tape recorders. One type of device utilizes a cartridge housing similar to that of a video tape cassette. A pair of tape reels is rotatably mounted in the housing. A cleaning tape is wound on the two tape reels in the same way as a video recording tape is wound on the tape reels of the video tape cassette. At a proper location on the path of the cleaning tape is mounted a detergent storage unit, which can press against the outer surface of the cleaning tape. The cleaning device can be put into the compartment of the video tape recorder in the same manner that one would install a video cassette. At the touch of the RECORDING or PLAY key, the cleaning tape is driven forward, first through the detergent storage unit for receiving a coating of detergent, and then against the surface of the head to coat the surface dirt with detergent. As the detergent storage unit is stationary, the cleaning tape will be wet with detergent after passing through the detergent storage unit. All portions of the cleaning tape that have passed by the head are wet. The wet cleaning tape can only brush aside dirt from the head surface and is unable to clean it effectively.
Another known device adapted the detergent storage unit into cylindrical form, driven and rotated by the cleaning tape. As only part of the circumference of the detergent storage unit can ooze detergent, the cleaning tape develops alternate wet and dry portions. The wet portions dissolve dirt on the head, which is then absorbed by the dry portions. After sustained alternating dry and wet, the dirt can be effectively cleaned away. But its drawback is that the rotating motion of the cylindrical detergent storage unit fully depends on the friction force between its surface and the cleaning tape. Therefore, the linear speed of the cleaning tape and that of the cylindrical detergent storage unit are not the same. This is apt to lead to unstable linear speed or even failure of rotation of the detergent storage unit.
Moreover, in the known devices discussed above, the cleaning tape, when dirty, cannot be changed. The entire cartridge housing must be discarded. Also, there is no proper position in which to place the detergent bottle.
Therefore, the main purpose of this invention is to overcome the unsolved problems of the various known cleaning devices. A driving device is mounted between the detergent storage unit and the nearer tape reel for rotating the detergent storage unit through the agency of the driven tape reel in order to maintain an equivalency between the linear speed of the former and that of the latter. A constant ratio between the length of the dry portion and that of the wet portion on the cleaning tape must be maintained.
The invention also provides a loading chamber that can be conveniently opened, and detachable tape reels so that users can conveniently replace a used cleaning tape with a new one. This invention also provides a compartment in the above-mentioned loading chamber for storage of the detergent bottle.